Answer: In most casesExplanation: In early formulations it often contained white asbestos fibers. When asbestos was banned in ceiling treatments by the Clean Air Act of 1978 in the United States, popcorn ceilings fell out of favor in much of the country. However, in order to minimize economic hardship to suppliers and installers, existing inventories of asbestos-bearing texturing materials were exempt from the ban, so it is possible to find asbestos in popcorn ceilings that were applied through the 1980s.